CEN/TR 15276-2:2009

Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance

This document specifies requirements and describes the methods for the design, installation, testing, maintenance and safety of condensed aerosol extinguishing systems and the characteristics of the extinguishant media and types of fire for which it is a suitable extinguishing medium.
This document also covers the use of condensed aerosol extinguishing systems for total flooding applications in normally unoccupied and unoccupiable areas, primarily related to buildings, plant and other specific applications, utilising electrically non-conducting aerosol fire extinguishants and for which there are sufficient data available to enable validation of performance characteristics by an appropriate independent authority.
This document is intended as a standard covering solely condensed aerosol.
This document is not applicable to explosion suppression applications.
This document is not intended to indicate approval of the extinguishants listed herein by the appropriate authorities, as other extinguishants may be equally acceptable.
This document is applicable to the extinguishants which fulfil CEN/TR 15276-1.

Ortsfeste Brandbekämpfungsanlagen - Löschanlagen für kondensierte Aerosole - Teil 2: Planung, Installation und Wartung

Dieses Dokument legt Anforderungen fest und beschreibt die Verfahren für die Planung, Installation, Prüfung,
Instandhaltung und Sicherheit von Aerosol-Löschanlagen sowie die Kenndaten der Löschmittel und deren
Eignung für die verschiedenen Brände.
Dieses Dokument beschreibt ebenfalls den Einsatz von Löschanlagen für kondensierte Aerosole als
Raumschutzanlagen in gewöhnlich unbesetzten und nicht begehbaren Räumen, hauptsächlich hinsichtlich
Gebäuden, Anlagen und weiteren besonderen Anwendungen, bei denen elektrisch nicht leitende Aerosol-Löschmittel
eingesetzt werden, über die gegenwärtig ausreichend viele Angaben verfügbar sind, so dass ihre
Kenndaten durch eine zuständige, unabhängige Institution bestätigt werden können.
Diese Europäische Norm gilt nicht für die Explosionsunterdrückung.
Dieses Dokument stellt keine Auflistung der von zuständigen Stellen zugelassenen Löschmittel dar, weitere,
hier nicht aufgeführte Löschmittel können ebenfalls akzeptabel sein.

Installations fixes de lutte contre l'incendie - Systèmes d'extinction à aérosol - Partie 2 : Calcul, installation et maintenance

Le présent document spécifie les exigences et décrit les méthodes de conception, d’installation, d’essai, de maintenance et sécurité des systèmes d'extinction à aérosol de condensation et les caractéristiques des agents d'extinction, et les types de feux pour lesquels ils sont appropriés.
Le présent document couvre également l'utilisation des systèmes d'extinction à aérosol de condensation pour des applications de noyage total dans des zones habituellement inoccupées et non occupables, principalement liées aux bâtiments, usines et d'autres applications spécifiques, utilisant des agents extincteurs en aérosol électriquement non conducteurs et pour lesquels des données suffisantes sont disponibles afin de permettre la validation des caractéristiques de performance par une autorité indépendante appropriée.
Ce document ne s’applique qu’aux aérosols de condensation.
Le présent document n'est pas applicable aux applications de suppression d'explosion.
Le présent document n'est pas destiné à indiquer l'approbation des agents extincteurs énumérés ici, par les autorités compétentes, car d'autres agents extincteurs peuvent être également acceptables.
Le présent document s'applique aux agents extincteurs qui satisfont au CEN/TR 15276-1.

Vgrajeni gasilni sistemi - Sistemi za gašenje s kondenziranim aerosolom - 2. del: Načrtovanje, vgradnja in vzdrževanje

General Information

• Status: Withdrawn
• Publication Date: 13-Jan-2009
• Withdrawal Date: 13-Apr-2025
• ICS: 13.220.20 - Fire protection
• Technical Committee: CEN/TC 191 - Fixed firefighting systems
• Drafting Committee: CEN/TC 191/WG 6 - Gas extinguishing Systems and components
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 27-Mar-2019
• Completion Date: 14-Apr-2025
• Ref Project: SIST-TP CEN/TR 15276-2:2009 - Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance

Relations

• Replaced By: EN 15276-2:2019 - Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2009
9JUDMHQLJDVLOQLVLVWHPL6LVWHPL]DJDãHQMHVNRQGHQ]LUDQLPDHURVRORPGHO
1DþUWRYDQMHYJUDGQMDLQY]GUåHYDQMH
Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design,
installation and maintenance
Ortsfeste Brandbekämpfungsanlagen - Löschanlagen für kondensierte Aerosole - Teil 2:
Planung, Installation und Wartung
Installations de lutte contre l'incendie - Systemes d'extinction a aérosol - Partie 2 :
Calcul, installation et maintenance
Ta slovenski standard je istoveten z: CEN/TR 15276-2:2009
ICS:
13.220.10 Gašenje požara Fire-fighting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 15276-2
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
January 2009
ICS 13.220.20
English Version
Fixed firefighting systems - Condensed aerosol extinguishing
systems - Part 2: Design, installation and maintenance
Installations fixes de lutte contre l'incendie - Systèmes Ortsfeste Brandbekämpfungsanlagen - Löschanlagen für
d'extinction à aérosol - Partie 2 : Calcul, installation et kondensierte Aerosole - Teil 2: Planung, Installation und
maintenance Instandhaltung
This Technical Report was approved by CEN on 9 September 2008. It has been drawn up by the Technical Committee CEN/TC 191.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15276-2:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .4
Introduction .5
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Use and limitations . 10
4.1 General . 10
4.2 Extinguishants . 11
4.2.1 General . 11
4.2.2 Extinguishing mechanism . 11
4.3 Potentially explosive atmosphere . 11
4.4 Temperature limitations . 11
5 Safety . 12
5.1 Hazard to personnel . 12
5.2 Safety precautions . 12
5.2.1 General . 12
5.2.2 Normally unoccupied areas . 13
5.2.3 Unoccupiable areas . 14
5.2.4 Installer’s responsibility . 14
5.2.5 User’s responsibility . 15
5.3 Electrical hazards . 15
5.3.1 General . 15
5.3.2 Electrical earthing . 15
5.3.3 Electrostatic discharge . 15
6 System design . 15
6.1 General . 15
6.2 Specifications, plans and approvals. 16
6.3 Enclosures . 16
6.3.1 Protected enclosure . 16
6.3.2 Openings . 16
6.3.3 Unclosable openings . 16
6.3.4 Ventilation and services . 16
6.3.5 Venting requirements . 16
6.4 Design factor requirements . 17
6.5 Design factor adjustment . 18
6.5.1 Effects of altitude . 18
6.5.2 Effects of temperature . 18
6.5.3 Effects of ventilation . 19
6.5.4 Compensation for Leakage through enclosure openings . 19
6.6 Design quantity . 19
6.7 Unit size and quantity of aerosol generators . 19
6.7.1 Aerosol generator size selection . 19
6.7.2 Quantity of aerosol generator . 20
6.8 Duration of protection . 21
6.9 System discharge . 21
6.9.1 Discharge time . 21
6.9.2 Extended discharge . 21
6.10 Plans . 21
7 System installation . 22
7.1 General . 22
7.2 Aerosol generator arrangement . 22
7.3 Operating conditions . 23
7.4 Installation recommendations . 23
7.5 System operation . 23
7.5.1 General . 23
7.5.2 Automatic operation . 23
7.5.3 Manual operation . 23
7.5.4 System isolate switch (lock off device) . 23
8 Detection, alarm and control systems . 24
8.1 General . 24
8.2 Automatic detection . 24
8.3 Operating devices . 24
8.3.1 General . 24
8.3.2 Automatic operation . 24
8.3.3 Manual operation . 25
8.4 Control equipment . 25
8.4.1 Electric control equipment . 25
8.4.2 Pneumatic control equipment . 25
8.4.3 Operating alarms and indicators . 25
8.4.4 Time delay device . 26
8.4.5 Control and indicating equipment . 26
9 Commissioning and acceptance . 26
9.1 General . 26
9.2 Tests . 27
9.2.1 General . 27
9.2.2 Enclosure check . 27
9.2.3 Review of mechanical components . 27
9.2.4 Review of enclosure integrity . 27
9.2.5 Review of electrical components . 28
9.2.6 Preliminary functional tests . 28
9.2.7 System functional operational test . 29
9.2.8 Remote monitoring operations (if applicable) . 29
9.2.9 Control panel primary power source . 29
9.3 Completion of functional tests . 29
9.4 Completion certificate and documentation . 29
10 Inspection . 30
10.1 General . 30
10.2 Inspection . 30
10.2.1 General . 30
10.2.2 Enclosures . 30
11 Maintenance . 31
11.1 General . 31
11.2 User's programme of inspection . 31
11.3 Service schedule . 31
12 Training. 31
Annex A (normative) Working documents . 32
A.1 General . 32
A.2 Working documents . 32
Bibliography . 33

Foreword
This document (CEN/TR 15276-2:2009) has been prepared by Technical Committee CEN/TC 191 “Fixed
firefighting systems”, the secretariat of which is held by BSI.
This document has the general title Fixed firefighting systems — Condensed aerosol extinguishing systems
and will consist of the following parts:
 Part 1: Requirements and test methods for components;
 Part 2: Design, installation and maintenance.
Introduction
It has been assumed in the preparation of this document that the execution of its provisions is entrusted to
appropriately qualified and experienced people in the specification, design, installation, testing, approval,
inspection, operation and maintenance of systems and equipment, for whose guidance it has been prepared,
and who can be expected to exercise a duty of care to avoid unnecessary release of extinguishant.
Product certification: Users of this document are advised to consider the desirability of independent
certification of product conformity with this document based on testing and continuing surveillance, which may
be coupled with assessment of manufacturer quality systems against EN ISO 9001.
Fire-fighting systems covered in this document are designed to provide a supply of fixed condensed aerosol
extinguishing medium to extinguish fire.
The requirements of this document are made in the light of the best technical data known to the working group
at the time of writing but, since a wide field is covered, it has been impracticable to consider every possible
factor or circumstance that might affect implementation of the requirements.
It is important that the fire protection of a building or plant be considered as a whole. Aerosol extinguishant
systems form only a part of the available facilities, but it should not be assumed that their adoption necessarily
removes the need to consider supplementary measures, such as the provision of portable fire extinguishers or
other mobile appliances for first aid or emergency use, or to deal with special hazards.
Small scale fire tests, comparable with the test methods mentioned in this standard, indicate that aerosol
extinguishants can be recognized as effective media for the extinction of certain Class A fires (solid surface
burning fires) and Class B and Class C fires according to EN 2, but it should not be forgotten, in the planning
of comprehensive schemes, that there may be hazards for which these mediums are not suitable, or that in
certain circumstances or situations there may be dangers in their use requiring special precautions.
Advice on these matters can be obtained from the appropriate manufacturer of the aerosol generators or the
extinguishing system. Information may also be sought from the appropriate fire authority, the health and safety
authorities and insurers. In addition, reference should be made as necessary to other national standards and
statutory regulations.
It is essential that fire-fighting equipment, the enclosure and the protected occupancy is carefully maintained
and managed to ensure instant readiness when required and effectiveness of the protection. Routine
maintenance is liable to be overlooked or given insufficient attention by the owner of the system. It is,
however, neglected at peril to the lives of occupants of the premises and at the risk of crippling financial loss.
The importance of maintenance cannot be too highly emphasised.
Condensed aerosol may contain traces of toxic substances like those produced by a fire, and will obscure
vision like smoke from fire. This standard requires, as a precaution, that the room is evacuated and sealed off
whenever a generator is activated - much like recommended response to fires. Precautions include
evacuation of the proximity area, criteria for re-entering and other safeguards as stated in paragraph 5.
1 Scope
This document specifies requirements and describes the methods for the design, installation, testing,
maintenance and safety of condensed aerosol extinguishing systems and the characteristics of the
extinguishant media and types of fire for which it is a suitable extinguishing medium.
This document also covers the use of condensed aerosol extinguishing systems for total flooding applications
in normally unoccupied and unoccupiable areas, primarily related to buildings, plant and other specific
applications, utilising electrically non-conducting aerosol fire extinguishants and for which there are sufficient
data available to enable validation of performance characteristics by an appropriate independent authority.
This document is intended as a standard covering solely condensed aerosol.
This document is not applicable to explosion suppression applications.
This document is not intended to indicate approval of the extinguishants listed herein by the appropriate
authorities, as other extinguishants may be equally acceptable.
This document is applicable to the extinguishants which fulfil CEN/TR 15276-1.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 54 (all parts), Fire detection and fire alarm systems
EN 12094-1, Fixed firefighting systems — Components for gas extinguishing systems — Part 1:
Requirements and test methods for electrical automatic control and delay devices
CEN/TR 15276-1:2009, Fixed firefighting systems — Condensed aerosol extinguishing systems — Part 1:
Requirements and test methods for components
EN 50110, Operation of electrical installations

3 Terms and definitions
For the purposes of this document, the terms and definitions given in CEN/TR 15276-1:2009 and the following
apply.
3.1
actuating mechanism
automatic or manual activation leading to the physical discharge of extinguishant
3.2
approved
acceptable to a relevant authority
3.3
authority
organisation, office or individual responsible for approving equipment, installations or procedures in
determining acceptability
NOTE The authority may base acceptance on conformity to the appropriate standards.
3.4
automatic
performing a function without the necessity of intentional intervention
3.5
automatic/manual switch
means of converting the system from automatic to manual actuation
NOTE This may be in the form of a manual switch on the control panel or other units, or a personnel door interlock. In
all cases, this changes the actuation mode of the system from automatic and manual to manual only or vice versa.
3.6
clearance
3.6.1
electrical clearance
unobstructed air distance between extinguishing system equipment and unenclosed or uninsulated live
electrical components not at ground potential
3.6.2
thermal clearance
air distance between a condensed aerosol generator and any structure or components sensitive to the
temperature developed by the generator
3.7
competent person
designated person, suitably trained, qualified by knowledge and practical experience and with the necessary
instructions to enable the required tests and examinations to be carried out
3.8
condensed aerosol
extinguishing medium consisting of finely divided solid particles and gaseous matter, these being generated
by a combustion process of a solid aerosol-forming compound
3.9
condensed aerosol generator
non-pressurised device which, when activated, generates an aerosol
NOTE It includes the mounting brackets.
3.10
control device
device which is able to control the sequence of events leading to the activation
3.11
coolant
heat absorbing medium or process
3.12
design application density (g/m )
extinguishing factor multiplied by the safety factor, required for system design purposes
NOTE 1 The design factor is expressed in grams per cubic metre.
NOTE 2 Extinguishing factor and design factor have been introduced as an alternative to extinguishing concentration
and design concentration respectively as concentration of the actual aerosol cannot be measured or even assessed in
some cases (the discharged medium, apart from the condensed aerosol, may contain products of the thermal
decomposition of a chemical coolant).
3.13
design quantity
mass of solid aerosol-forming composition necessary to achieve the design factor (density) in the maximum
protected volume of a specific risk
NOTE The design quantity is expressed in grams.
3.14
discharge time
time from the generator activation to the end of its discharge
3.15
extinguishing application density
the minimum mass of a specific aerosol-forming compound per cubic meter of enclosure volume required to
extinguish fire involving a specific fuel under defined experimental conditions, using a specific aerosol
generator type and size, excluding any safety factor.
NOTE The extinguishing factor is expressed in grams per cubic metre.
3.16
family
group of generators with same solid compound, same kind of cooling device, same kind of discharge outlet,
same ignition device, same layout and same internal/external architecture
3.17
holding time
period of time during which the extinguishant is required to maintain at least the extinguishing application
density throughout the protected area/volume.
3.18
hot work
grinding, welding, thermal or oxygen cutting or heating and other related heat-producing or spark-producing
operations
3.19
ignition device
device which is able to ignite the solid aerosol-forming compound
3.20
inspection
visual check to give a reasonable assurance that the extinguishing system is ready to operations
3.21
listing authority
recognized fire protection testing and approval body (notified laboratory)
3.22
location drawing
plan of the risk clearly indicating the as-installed location of all aerosol generators, controls and maintenance
isolate switch (lock off devices)
3.23
lock-off device
manual shut-off device that prevents the electrical actuation of aerosol generators
NOTE The device operation provides an indication of system isolation.
3.24
lowest observed adverse effect level
LOAEL
lowest agent factor at which an adverse toxicological or physiological effect has been observed
3.25
maintenance
thorough check to give maximum assurance that the extinguishing system will operate as intended
NOTE It includes a thorough examination and any necessary repair or replacement of system components.
3.26
manual
requiring intentional intervention to accomplish a function
3.27
manufacturer
legal person that is responsible for the design, manufacturing, packaging and quality insurance of a device
before it is placed on the market
3.28
monitoring
supervision of the operating integrity of an electrical, mechanical, pneumatic or hydraulic control feature of a
system
3.29
no observed adverse effect level
NOAEL
highest agent factor at which no adverse toxicological or physiological effect has been observed
3.30
normally unoccupied area
area that is not occupied by persons under normal circumstances but may be entered occasionally for brief
periods
3.31
protected volume
volume enclosed by the building elements around the protected enclosure, minus the volume of any
permanent impermeable building element within the enclosure
3.32
release
physical discharge or emission of an aerosol as a consequence of the generator actuation
3.33
safety factor
multiplier of the extinguishing factor to determine the aerosol design factor
3.34
solid aerosol-forming compound
mixture of oxidant, combustible component and technical admixtures producing fire extinguishing aerosol
upon ignition
3.35
supplier
legal person that is responsible for the product and is able to ensure that its quality is ensured
3.36
system isolate switch
see lock-off device (3.23)
3.37
thermal ignition device
device, which automatically operates at a rated temperature and is arranged for the ignition of the solid
aerosol-forming compound
3.38
total flooding system
fire-fighting system arranged to discharge extinguishant into an enclosed space to achieve the appropriate
design factor
3.39
unoccupiable area
area which cannot be occupied due to dimensional or other physical constraints e.g. shallow voids, cabinets
3.40
user
legal person, whom the system is designed for, and who is responsible for operation and to ensure the
consistency of performance as described by the supplier and to follow the legal regulations
4 Use and limitations
4.1 General
The design, installation, service and maintenance of aerosol generators should be performed by those
competent persons in fire extinguishing system technology.
The hazards against which these aerosol generators offer protection, and any limitations on their use, should
be contained in the system supplier’s design manual.
The total flooding use of aerosol generators is primarily for protection against hazards that are within an
enclosure that will permit to establish and maintain the appropriate design factor of condensed aerosol for the
required period of time to assure an effective extinguishment. Local applications are not covered by this
standard.
Effects of agent particulate residue on sensitive equipment and other objects should be considered when
using condensed aerosol extinguishing agents in spaces containing that type of equipment.
4.2 Extinguishants
4.2.1 General
The extinguishants referred to in this document are electrically non-conductive media.
The extinguishants and specialised system parameters are each covered individually in CEN/TR 15276-1 for
specific extinguishants which should be used in conjunction with this document.
The extinguishants referred to in CEN/TR 15276-1 should not be used on fires involving the following unless
relevant testing has been carried out to the satisfaction of the Authority:
a) chemicals containing their own supply of oxygen, such as cellulose nitrate;
b) mixtures containing oxidizing materials, such as sodium chlorate or sodium nitrate;
c) chemicals capable of undergoing autothermal decomposition, such as some organic peroxides;
d) reactive metals (such as sodium, potassium, magnesium, titanium and zirconium), reactive hydrides, or
metal amides, some of which may react violently with the extinguishants;
e) oxidizing agents such as nitric oxides and fluorine;
f) pyrophoric materials such as white phosphorous or metallo-organic compounds.
The above list may not be exhaustive.
4.2.2 Extinguishing mechanism
Condensed aerosol is an extinguishing media consisting of finely divided solid particles (e.g. 40 % by mass)
typically based on alkali metal salts and gases (e.g. 60 % by mass), mainly comprised of nitrogen, carbon
dioxide and water vapour.
Aerosol extinguishes fires chemically, interfering with the flame chain reaction by removing the reactive free
radicals and physically, by cooling the seat of the fire. Both actions take place mainly on the surface of the
aerosol particles, and as such, the finer the particles the more effective the extinguishment.
4.3 Potentially explosive atmosphere
Under certain conditions the potential for explosive atmospheres may exist. Areas where such potential may
exist are classified as hazardous. Condensed aerosols may be used in hazardous areas subject to the
manufacturer obtaining the specific listings and approvals for such areas from the appropriate authorities.
Where aerosol generators are used in potentially explosive atmosphere, the compatibility of the generator to
the atmosphere for the determined lifetime should be assessed.
IMPORTANT — The EU Directive 94/9/EC (ATEX Directive) should be taken into consideration.
4.4 Temperature limitations
All devices should be designed for the service they will encounter and should not readily be rendered
inoperative or susceptible to accidental operation.
Devices normally should be designed to function properly from – 20 °C to + 50 °C, or marked to indicate
temperature limitations, or in accordance with manufacturers’ specifications which should be marked on the
name-plate, or (where there is no name-plate) in the manufacturer’s instruction manual.
For condensed aerosols a special care should be used to determine the maximum ambient temperature at
which the aerosol generator can be installed, without risk of actuation by temperature itself.
The condensed aerosol generators should not be employed at less than the minimum thermal clearance
distances specified in the manufacturer’s instruction manual.
5 Safety
5.1 Hazard to personnel
Any hazard to personnel created by the actuation and discharge of the condensed aerosol generators should
be considered in the design of the protection in particular with reference to the hazards associated with
particular extinguishants. When selecting a condensed aerosol extinguishant a careful consideration should
be given to independent occupational health and safety data.
Adherence to this document does not remove the user’s statutory responsibility to comply with the appropriate
safety regulations.
The discharge of a condensed aerosol generator may create serious hazards for personnel in both the
protected area and areas to which it may migrate. These hazards include the following:
a) Reduced visibility: when activated, condensed aerosol generators reduce visibility both during and after
discharge period.
b) Potential toxicity: when activated, condensed aerosol generators may produce toxic levels of gases such
as carbon monoxide, nitrogen oxides and ammonia, which are typical by-products of the aerosol
generating reaction. Actual concentrations of these by-products depend on the chemical compositions of
the solid aerosol-forming compound and coolant, engineering design of the aerosol generators and
conditions of the enclosure under protection. Maximum allowable exposure to a design factor of the
aerosol under conditions of a sealed enclosure should be provided for each agent by its manufacturer.
Any possible adverse effects on humans that may be experienced at the indicated allowable exposures
should be described. The information should be supported by the appropriate test results on chemical
composition of the aerosol and its short term “acute” adverse effects. The results should be endorsed by
an independent testing laboratory having an appropriate authority.
c) Thermal hazard: a condensed aerosol discharges at the elevated temperatures. Depending on the
intended application(s) of the aerosol system, the temperature at the reasonable minimum clearance from
the discharge outlet, as specified by the manufacturer of the aerosol generators, should not exceed 75 °C
for persons, 200 °C for combustible material and 400 °C for construction structures respectively.
Immediately after discharge the aerosol generators can be hot, therefore, protective gloves shall be worn
before handling generators up to 15 min after discharge.
d) Turbulence: turbulence caused by high-velocity discharge from the nozzle may be enough to dislodge
substantial objects directly in its path, such as ceiling tiles and light fittings. Therefore, tiles and light
fittings should be properly secured. Aerosol discharge may also cause enough general turbulence to
move unsecured paper and light objects.
NOTE In order to assess the potential human health effects manufacturers should conduct the toxicity testing for use.
This requires direct toxicity assessment on the aerosol after discharge of the system at the maximum design factor.
5.2 Safety precautions
5.2.1 General
Reduced visibility during and after discharge together with potential toxicity restricts the use of a condensed
aerosol total flooding system to normally unoccupied and unoccupiable areas only. In any proposed use of
condensed aerosol where there is a possibility that people may enter the protected enclosure or be close to
the protected risk, suitable safeguards such as personnel training, warning signs, pre-discharge alarms and
system isolate switches should be provided. Means of ventilation after fire should be readily available.
Unnecessary exposure to a condensed aerosol should be avoided.
Following the use of a condensed aerosol, personnel should not enter the protected area until it has been
thoroughly ventilated. Venting of the post-fire atmosphere should be to an open-air area, where possible, to
prevent the inadvertent exposure of personnel to any combustion products of the fire and aerosol-generating
reaction. In case of fire involving unknown products it is imperative to check the concentration of carbon
monoxide and other potentially toxic gases before entering the premises.
Following a system discharge the aerosol that has settled should be removed in accordance with the
manufacturer’s recommendations. Protective clothing including gloves and goggles should be worn. A
respirator or mask may be required.
Venting in to an open-air area should also prevent contamination/migration of extinguishant to other areas
than the protected area.
5.2.2 Normally unoccupied areas
If there are no regulations available, the following minimum requirements should be taken (see Table 1).
The maximum factor should not exceed the LOAEL for the extinguishant used unless a lock-off device is
fitted.
It is recommended that systems where the NOAEL is expected to be exceeded be placed in non-automatic
mode whilst the room is occupied.
Table 1 — Minimum safety precautions
Maximum factor Time delay device Automatic/manual switch Lock-off device
Up to and including the Required Not Required Not Required
NOAEL
Above the NOAEL and up Required Required Not Required
to the LOAEL
LOAEL and above Required Required Required
NOTE The intent of this table is to avoid unnecessary exposure of occupants to the discharged extinguishant.
Factors such as the time for egress and the risk to the occupants by the fire should be considered when determining
the system discharge time delay. Where national standards require other precautions, these should be implemented.

In case of unknown NOAEL and LOAEL values, it should be presumed above LOAEL value (see Table 1).
WARNING — Any change to the enclosure volume, or addition or removal of contents that was not
covered in the original design will affect the design factor. In such cases, the system should be
recalculated to ensure that the system with the new design factor is consistent with Table 1.
The following general safety aspects should apply for areas protected by the condensed aerosol total flooding
systems and which are capable of being occupied:
a) Time delay devices:
1) extinguishing systems should incorporate a pre-discharge alarm with a time delay sufficient to allow
personnel evacuation prior to discharge;
2) time delay devices should be used only for personnel evacuation or to prepare the hazard area for
discharge.
b) Automatic/manual switch and lock-off devices at the entrance to the protected area where required in
accordance with Table 1.
NOTE Although lock-off devices are not always required, they are essential in some situations, particularly for some
specific maintenance functions.
c) Thermal automatic activation device should not be used in normally unoccupied areas.
d) Exit routes which should be kept clear at all times, and emergency lighting and adequate direction signs to
minimise travel distances.
e) Outward-swinging self-closing doors which can be opened from the inside, including when locked from the
outside.
f) Continuous visual and audible alarms at entrances and designated exits inside the protected area and
continuous visual alarm outside the protected area which operate until the protected area has been made
safe.
g) Appropriate warning and instruction signs.
h) Where required, pre-discharge alarms within such areas that are distinctive from all other alarm signals
that will operate immediately upon detection of the fire.
i) Means for prompt natural or, where necessary, forcer-draft ventilation of such areas after any discharge of
extinguishant. Care should be taken to completely dissipate hazardous atmospheres and not just move
them to other locations.
j) Instructions and drills of all personnel within or in the vicinity of protected areas, including maintenance or
construction personnel who may be brought into the area, to ensure their correct actions when the system
operates.
In addition to the above requirements, the following are recommended:
 self-contained breathing apparatus should be supplied and personnel trained in its use;
 personnel should not enter the enclosure until it has been verified as being safe to do so.
5.2.3 Unoccupiable areas
The maximum factor may exceed the LOAEL for the extinguishant used, without the need for a lock-off device
to be fitted.
5.2.4 Installer’s responsibility
The installer should be responsible for the provision of the following:
a) Warning and instruction signs in accordance with 8.4.3 and 8.4.5.
b) Alarms within the area that will operate immediately on detection of fire.
c) Continuous alarms at the entrance to the protected area to be sounded until the atmosphere has been
restored to normal.
d) Instruction to disarm the system during periods of inspection, maintenance or modification.
e) Instruction to the owner to remove aerosol generator(s) before allowing any hot work to be conducted
inside the protected area.
f) System isolating switches / lock-off devices at least at one entrance to the protected area.
5.2.5 User’s responsibility
The user should be responsible for the provision of the following:
a) Written procedures appropriate to the risk, instruction and drills of all personnel within or near the
protected area.
b) Adeq
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